Mount-finishing machine



Aug. 13, 1929. A. SITTEL 1,724,732

MOUNT FINISHING MACHINE Filed Jan. 30, 1928 Inventor: A|F1-ed Sittel,

His Attorneg.

Patented Aug. 13,1929.

UNITED STATES PATENT OFFICE.

1.1mm) sum, orrmm, GERMANY, assrenon 'ro' GENERAL nnac'rnro COMPANY,

A. CORPORATION OF NEW YORK.

moummnusnmo MACHINE.

Application filed January so, 1928, Serial No. 250,688, and in Germany Imam, 1927.

The invention relates to the manufacture ject is to facilitate the finishing f the mounts by which is meant the glass stems provided with one or several filaments. To this end there is, in accordance with the invention, combined with a furnace for degassing the nickel or other metal parts, and

also the joints between the filament and the leads, a gettering device for gettering the mount, that is, applying to the filament or filaments, a coating'of getter, or material for hindering the blackening of the bulb, and

1 this gettering device is combined in a unit with the furnace. The combination is here effected by the use of an endless conveyor chain, which carries the mounts through the furnace and past the gettering device, so

that the mounts are continuously and without being changed or handled, first degassed and then the filaments, previously attached 'to the stems to form the mounts, are coated with a getter. In order that the operation of the machine may be observed and further to save providing the furnace with a special vent for the reducing gas traversing it, the furnace is preferably made in the form of a U shaped tunnel with downwardlydirected.

legs, in the bight or connecting bridge of which there is-mounted a heater and into which the feed for the reducing gas opens, whilstthrough the furnace legs, open at the bottom, the products of the reduction flow off freely.

In the accompanying drawing there is shown merely for purposes of illustration one example of a machine constructed in accordance with the invention and in which Fig. 1 is a longitudinal section, partly diagrammatic, of the machine and Figs. 2 to 4 are views in elevation of some forms of mounts for miniature electric incandescent lamps and similar devices, such as may be treated in the machine shown in Fig. 1.

. On a frame not shown there is mounted a furnace casing 1 having the general form of 'a' bell or inverted cup and preferably U shaped with the open legs pointing downward- Through the furnace casing runs a part of a conveyor, su'ch as a chain 2, travelling in a 'ver tical plane and carried on two rollers 3 and 4 inside the furnace and several other rollers, such as 5, .6, 7 located beneath tervals with mount holders 12, pivoted for example on bolts on the chain so as to swing freely, and having their bottom ends formed as weights or else provided with weights 13 by which the pivoted holders 12 are kept in an approximtely upright position. The mount holders 12 attached to the conveyor chain hold the common type of stem for miniature electric incandescent lamps by gripping the downwardly projecting exhaust tubes 14 of the stems which with their filaments constitute the mounts of the types shown, for example, in Figures 2'to 4:. In the mount constructed as shown in Figure 2 a single filament 15 is soldered or clamped to two comparatively thick nickel 0r iron leads 16, which are connected to the leading-in wires 17 sealed into the pinch 18 of the stem tube 19. The mount shown in Figure 3 has two filaments 15, 15 fastened to three nickel or iron leads 16. The mount shown in Figure 4 has in addition to the two filaments 15, 15" and the three relatively thick nickel or iron leads 16, a screen or plate 20 partly surrounding the filament 15', and made of a metal such as nickel, which must be degassed.

In the horizontal bridge or connecting part of the U shaped furnace casing 1 there is provided above the upper horizontal run of the conveyor chain 2 a heater formed, in the example shown, as a U shaped or bent electric heating element 21 rendered incandescent by' the passage of current. The current leads 22 of this heater 21 are carried by insulators,

through the furnace wall and connected to the secondary coil of a transformer 23. In the bridge or connecting part of the furnace casing 0r tunnel and above the heater there is a reducing gas inlet or conduit 26 provided with a number of outlets 24 and with a control cock 25 for feeding-into the furnace a reducing gas such as hydrogen. The reducing gas constantly fills the upper part of the furnace, on account'of its light weight, and the excess escapes at theopen ends of the downwardly T projecting legs of the-furnace. While pass-l:

ing through the heater the nickel and iron parts and also the joints'between the filament and the leads, are close to the heater and are heated by radiant heat to a high degree and degassed while at the same time any oxides which may be present on the metals of the stem are reduced to metal by the reducing gas whereby the development of harmful oxides on the mount are prevented. A peephole 27 arranged in the side wall of the tunnelshaped furnace casing permits at all times observation of the heater 21 and the control of the heating of the metal of the mounts traveling through the heater.

Adjoining the furnace 1 is a gettering device for applying the coating material or getter to the filaments of the mounts as soon as the mounts emerge from the furnace. This gettering device consists essentially of a spray nozzle 28 and an electrically heated drying oven 29 so arranged that the mounts on the conveyor chain travel past the gettering device continuously. Between the conveyor chain 2 and the spray nozzle 28 which is combined with asupply receptacle 30 for the coating material or getter suspension, there is a circular template 31 with a sector-shaped window 32. The size of this Window and the height of the template 31 combined with the proper setting of the spray nozzle 28, insure the spraying with getter of the filaments and the adjoining parts of the mounts, but not their lower parts and particularly not the flares and exhaust tube. The superfluous getter can be caught by a screen located behind the conveyor chain, but there maybe provided behind the conveyor chain 2 a collector 33 with a built-in ejector to suck olf and conduct away the superfluous coating material or getter.

.The drying oven 29 located beside the spray nozzle for the drying of the appliedcoating material or getter may have the usual tunnel shape and be heated by a built-in heating coil 34. In place of this oven there can also be used, as is well known, nozzles-through which drying air is directed against the mounts or the filaments coated with getter.

The mounts set on the conveyor chain 2 above the roller 5 are taken off the conveyor chain at the roller 7 and set byhandinto trays, by means of which they can be taken to a machine for sealing the stems into the bulbs. The stems may also be taken off the conveyor chain 2 automatically, for example by grippers, and thus be carried into a sealing-int machine set upbeside the mount finishing machine.

What I claim as new and desire to secure by' Letters Patent of the United States is 1. In a device of the character described,

the combination with a furnace comprising a casing containing a reducing atmosphere,

- and a heater in said casing of a conveyor hav-' ing mount holders 'to hold mounts with their filaments projecting from said holders, said conveyor being mounted to carry said mount holders through said furnace casing adjacent to but out of range of said heater and along a path such that only the filaments and adjoining metal parts of the mounts in said holders are within range of said heater and are heated by radiant heat until free of gas, and a sprayer mounted to direct its spray across said conveyor and onto said filaments in said mount holders as said mount holders emerge from said furnace.

2. In a device ofthe character described, the combination with a furnace comprising a casing in the shape of a tunnel like an inverted U with its legsextending downward, a heater mounted in-the horizontal portion of said tunnel, and a supply conduit discharging into the upper part of said casing for keeping said casing filled with reducing gas, of a conveyor having mount holders to hold mounts with their filaments projecting from said holders, said conveyor being mounted to carry said mount holders through said furnace casing adjacent to but out of range of said heater and along a path such that only the filaments and adjoining metal parts of the mounts in said holders are within range across the upper part of. the casing, and down.

the other leg, mount holders pivoted on said chain and weighted to tend to swing into a vertical position, a heater in the upper part of said casing adjacent but above the path of the upper ends of said holders, in position such that the filaments of mounts in said holders pass close enough to said heater to heat only said filaments and adjoining metal until free of gas, and a sprayer mounted to direct its spray across said conveyor and onto said filaments in said mount holders as said mount holders emerge from said furnace.

4. In a deyice of the character described, the combination with a furnace comprising a casing containing a reducing atmosphere and a heater in said casing, of a conveyor having mount holders constructed to hold mounts with their filaments projecting from said holders, said conveyor being mounted to carry said ount holders through said furnace casing a jacent to but out of range of said heater and along a path such that only the filaments and adjoining metal parts of the mounts in said holders "are within range of said heater and are heated by radiant heat until free of gas, asprayer nozzle mounted to direct its spray across said conveyor and onto said filaments in said mount holders as said mount holders emerge from said furnace, and a template between said spray nozzle and said conveyor having a window in register with the path of the filaments of the mounts in said mount holders.

5. In a device of the character described, a furnace having a casing in the form of an inverted cup, means for keeping said casing filled with a reducing atmosphere, a conveyor chain mounted with a horizontal run in the upper part of said casing, mount holders pivotally secured to said chain and biased to be vertical during their travel'along the hori zontal run of saidconveyor chain, an electric heater mounted adjacent to and above said horizontal run to heat a zone immediately above the upper ends of saidmount holders, and means for spraying getter material transversely of and immediately above the upper ends of said mount holders as they emerge from said casing.

6. In a device of the character described, a furnace having a casing in the shape of an inverted U with open legs extending downward, a conveyor chain mounted in said casing to travel up one leg, through the upper part of the casing in a horizontal run and down and out of the other leg, mount holders pivoted on said chain and weighted to be normally vertical, an electric heater having a heating coil and shaped like an inverted U, said heater being mounted above the horizontal run of said conveyor chain and above the upper ends of said holders in position such that only the filaments on mounts in said holders pass between the legs of said heater, means for maintaining a reducing atmosphere in said casing, and means for supplying current to said heater.

In Witness whereof, I have hereunto set my hand this 12th day of January, 1928.

ALFRED SITTEL. 

